In concrete roadway paving the delivering trucks may drive on the subgrade or base and deposit the freshly mixed concrete directly on the base. More generally this is not permitted or possible and the trucks must drive on the shoulder alongside the subgrade or base. A combined concrete placer and spreader is shown in my U.S. Pat. No. 3,267,824. FIG. 12 shows the machine with a projecting hopper to receiving the concrete directly from a delivery truck. The hopper may be retracted for each truck to allow it to pass the placer and spreader. As shown in my U.S. Pat. No. 3,611,890 the receiving conveyor may be a belt conveyor which is shifted laterally for that purpose. As shown in said patent, the finishing machine which follows the placer and spreader necessarily includes a secondary spreader and strike-off. In my U.S. Pat. No. 3,611,890 patent the latter machine is a slip-form paver.
The object of the present invention is to provide a versatile and relatively uncomplicated concrete placer. The machine does not include a spreader but is intended to operate immediately in front of a slip-form paver of the type shown in my U.S. Pat. No. 3,611,890 patent.
More particularly, it is an object of my invention to provide a concrete placer which can be used in paving roadways of any usual width including a double lane and also for paving alongside a finished slab or to receive the concrete from a truck which is on an adjacent but, elevated roadway.
Another object of my invention is to provide a placer having a plain, straight-run belt conveyor which can operate at high speeds.
Another object is to provide a simple and reliable mechanism which can move the conveyor endwise, that is, laterally respecting the roadway, with a well controlled acceleration and deceleration utilizing a relatively short, single operating cylinder.
Another object is to be able to raise the loading end of the conveyor where desired.